A breast cyst is an accumulation of fluid within the breast, often resulting in breast lump that you can feel. If you find any breast lump, whether you think it is a cyst or not, it is essential to consult your health care provider as soon as possible.
About 25% of breast cysts enlarge gradually into ‘big-enough’ cysts to become a palpable breast lump. Breast cysts are extremely common, and are thought to occur in as many as 1/3 of all women between the ages of 35 and 50.
It is important to note that breast cysts are a benign lesion and do not progress to breast cancer and do not increase the risk of cancer. However, depending upon the features of the cyst in particular, the amount of solid elements inside it, it might have the remote chance that a malignant breast cancer somewhere in the background is the root cause of the cyst. The chances of an epidermoid cyst actually being related to malignant breast cancer, however, are extremely low; not even a 1/2 % chance.
What is a cyst?
Here is an ultrasound picture of a cyst in the breast.
What causes a cyst?
Breast cyst walls usually occur in the terminal duct lobular unit (TDLU), or right where the lobules transfer the milk into the ducts.
In terms of the mechanics of breast functioning, when things go amiss, they tend to go amiss in the TDLU. It is possible that a cyst could be caused by swelling and lead to inflammatory breast cancer because of an infection, but this would tend to have other obvious clinical features (pain, redness, discharges), and would typically be a problem for pregnant and breast feeding women. Breast cysts tend to affect slightly older, premenopausal women (35-50), and are probably caused by variations in hormone levels as a woman approaches menopause. The fluid in a breast cyst is not milk, but a clear yellow fluid, the same fluid which most of the liquid matter of the body is composed of.
Are breasts cysts associated with breast cancer or risk of breast cancer?
As mentioned, a cyst is a benign build up of fluid. A cyst cannot ’cause’ cancer, and cannot ‘evolve into’ breast cancer. A breast cyst is an after-effect, unrelated to any kind of genetic cell-growth or metaplastic cells, which we usually associate with breast cancer and risk of breast cancer. So, when people talk about breast cancer risks associated with cysts, they are talking about the cyst as a diagnostic side effect really. If a cyst is not simple and homogeneous, but seems to have various complications or complexities, then there is a risk that these complexities are being caused by a malignant breast cancer which is imposing biological and cellular changes in the functioning of the breast ducts.
How are breast cysts discovered.
A mammographic image (X-ray) of a breast cyst cannot be reliably distinguished from solid masses (solid masses are far more likely to be associated with breast cancer), so they are typically referred to ultrasound.
Sonograms (ultrasound scans) are very useful at distinguishing between solid and liquid elements, and a ‘simple breast cyst’, which has a uniform oval shape, with thin smooth walls, and a homogeneous fluid filling, would be clearly evident. An experienced radiologist can, with the benefit of ultrasound, get a pretty clear picture of the benign nature of a breast cyst. If there are really curious features or evidence of solid particles or nodules, then a biopsy will likely be called for, usually by fine-needle aspiration.
Are there any other different types of classes of breast cysts?
At various times, different researchers have tried to propose various classification systems for breast cysts. These classifications, however, are not necessarily useful for experienced pathologists and radiologists. What they are looking for are any qualitative and dynamic aspects of the sebaceous cysts which differ from the norm, and the general course of action, once a cysts is drained, is follow-up and observation.
Here is a picture of a cyst on MRI
A continuum of cystic abnormalities: simple, complicated and complex.
A ‘simple breast cyst’ is one which is obviously fluid filled and has a very regular oval shape with thin, smooth walls. These are the most common and the most obviously benign breast cysts.
However, the make up of breast cysts, as well as ovarian cysts can become more ‘complicated‘ by other presenting features. A cyst usually appears alone, but sometime appears in small ‘clusters‘. (clustered microcysts.) If a breast cyst shows ‘septations‘ (septa, partitions or a loublated cyst), and so it appears to have two or more ‘sections’, this is another complication.
A cyst may also appear to have some ‘thicker’ sections of the walls, or small ‘nodular’ build ups, especially along the walls of the septations. Simple breast cysts, epidermal inclusion cysts, and cysts with septa or appearing in clusters are virtually always benign, so the likely recommendation will be for annual follow up only.
Complicated breast cysts usually need to be drained
But when there are thicker sections of the walls, that is when a breast cyst might begin to be referred to as a ‘complicated‘ cyst, and these are mostly, but not always benign. A ‘complicated’ cyst will probably be drained by fine needle aspiration under local anesthetic and probably with a shorter term follow-up.
A breast cyst has a mixture of fluid and solid elements is usually termed a ‘complex breast cyst’
If a breast cyst does not appear to be uniformly fluid-filled, but appears to have some solid elements, this changes the picture considerably. Cysts with a combination of fluid and suspended solid elements are usually called ‘complex‘ cysts, and if the solid elements are really prominent it might even be called a ‘complex cystic mass‘. Complex cysts will be taken more seriously by the physician, and will most likely be biopsied. About 5% of breast cysts take on this ‘complex’ presentation.
Breast cysts should have uniformly thin walls
A simple rule regarding the imaging diagnostics of a breast cyst is that it should have a uniformly thin smooth wall. If this uniformity is not present, then you have to worry about the part that isn’t thin and smooth, and whether to insert a needle to drain it, or just follow-it-up. It is a ‘subjective-continuum’ decision, not a black and white categorization with standardized treatment processes.
Treatment for Breast cysts.
Big breast cysts that you can feel, or that hurt and simple ‘internal’ breast cysts that you are unaware of, are really not associated with any sort of breast tumor cells developing. They tend to just be left alone with routine follow-up. If they are bothersome, they may be drained via needle aspiration.
‘Complicated’ and ‘complex’ cysts will likely be drained regardless. Smaller, internal cysts would typically be drained with ‘ultrasound guidance’ for the fine needle. The follow-up interval for a complex cyst will typically be a bit shorter, usually around 6 months.
Keep in mind that most of the women that have breast cancer, (whether it be ductal carcinoma in situ or an invasive breast cancer) are often in breast cancer support groups, so they can communicate and support other women who also have breast cancer.
OK, lets add some Questions and Answers from people.
- Why do I get pain before a menstrual period from my breast cyst? People only make guesses, nobody knows for sure, but it’s common.
- Why do breast cysts need to be removed? Two reasons: 1) When a woman says “I want it removed, dammit, because it hurts, and it keeps coming back after cyst aspiration“., or 2) surgically removed after a biopsy result was too abnormal.
- When are breast cysts dangerous? When an inexperienced doctor tries to aspirate it with a needle while the woman is sitting in a chair, and she feels faint and hits her head on the ground. THAT actually happens. So drain cysts while lying down, in the hands of a calming radiologist who uses ultrasound to guide the needle into the cyst.
- Why do breast cysts hurt? They occupy space where other breast tissue used to be. This breast tissue gets pushed away by the cyst, stretching or compressing the tissue, and some nerve endings for pain sensation start sending complaining signals to the brain about it. The other reason they are tender is because some people rub or palpate them too hard. You can make any body part hurt by touching it too much.
- My cyst had some debris inside, what is it? It’s A) nothing to worry about. B) it might be the remnant of some blood in the cyst from the past, or like the mucous inside of your cheek (not exactly, just an analogy). Cysts
- Are cysts absolutely benign? As mentioned, usually cysts are simple fluid filled sacs and are categorised along with other benign (non-cancerous) breast disorders such as hyperplasia, fibroadenomas, phyllodes tumor, papillary lesion, sclerosing adenosis and radial scars.
- Are there different types of cysts? There are many different classifications of cysts – often they relate to where they are found in the body such as arachnoid cysts (brain and spinal cord), pilonidal cyst (buttocks), ganglion cyst (occurs in any joint or tendon sheath),vallecular cyst (between the back of the tongue and throat), pineal cysts (pineal gland – brain), bone cysts, epidermal (epidermoid) cysts (skin), sebaceous cyst etc.
- Is adenoid cystic carcinoma (sometimes called cystic carcinoma) related to breast cancer? No, this is a very rare type of breast cancer and the malignant cells here are very similar to adeno cells (adeno cells are related to glandular secretions). Simple breast cysts, on the other hand, are a benign breast disease.
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